Answer to: iPhone 4 wifi signal issues greyed outI had this issue with my iPhone 4. I attempted all the suggestions, reset, replacing dock flex and standard Antenna, Freezing, heating, turning it on airplane mode and do not disturb and none worked for me. I FIXED THIS ISSUE by cleaning the gold contact at the top left of the motherboard and also cleaning the section of the Chassis which it contacts onto. I used Contact Cleaner however I believe any moisture will work provided it is allowed to dry in time. Good luck to all those with this issue.